1. Field of the Invention
The present invention relates to a display apparatus and a displaying method thereof, and more particularly, to a display apparatus and a displaying method thereof, which can improve picture quality.
2. Discussion of Related Art
A mobile communication terminal has been widely used because it is portable. To satisfy users' various demands, the mobile communication terminal has recently been manufactured with an image display function in addition to a voice communication function.
As the mobile communication terminal begins to display images, an image display part of the mobile communication terminal is becoming very important. An example of the image display part used in the mobile communication terminal is a liquid crystal display (LCD). The LCD rearranges liquid crystals and adjusts the transmittance of light emitted from a backlight in order to display an image. However, the LCD needs the backlight, which is provided separately, thereby consuming much power. Further, the LCD has problems of narrow view angle, slow response speed, low contrast, etc. To solve these problems of the LCD, a light emitting display (LED) can be substituted for the LCD, as the image display part of the mobile communication terminal. The LED has fast response speed, high contrast, low voltage drive, wide view angle, etc.
In addition, most mobile communication terminals are equipped with a camera for photographing an image. The camera generally uses a charge coupled device (CCD) sensor or a complementary metal oxide semiconductor (CMOS) sensor as an image sensing device. The CCD sensor includes color filters for red (R), green (G) and blue (B) colors to allow light of a predetermined wavelength to pass therethrough, and an RGB sensor to charge the light passing through the color filter. The CCD sensor then converts the amount of light charged in the RGB sensor into an electrical signal, thereby creating image data. By contrast, the CMOS sensor directly receives light through a semiconductor device without a filter and converts the light into an electrical signal, thereby creating image data.
In the mobile communication terminal, a predetermined image photographed by the camera can be displayed on the image display part (e.g., light emitting display). At this time, a user can estimate whether the picture quality is good or bad on the basis of the image displayed on the image display part.
However, in the conventional mobile communication terminal, the picture quality can be deteriorated by the surrounding environment; e.g., a predetermined portion of a subject to be photographed by the camera may become relatively bright due to direct sunlight shining on the predetermined portion or the like. In fact, when a predetermined portion of the subject is very bright, it is represented as white. Because the portion is represented as white, there arises a problem in that the brightness around this portion is also increased. When the mobile communication terminal processes the image data, the image data having gradation beyond a predetermined level is represented as white. Therefore, referring to FIG. 1, when the predetermined portion of the subject is relatively bright, a portion around that bright portion of the subject is also represented as white (referring to a center portion of FIG. 1). This effect is referred to as a white clip effect, which deteriorates the picture quality.